solving the problem of how to design a boat that would be small and light enough to transport easily on foot through wilderness, but robust enough to carry people in safety across wide bodies of water. His solution was to design a boat in which all components would double as items of clothing, or accessories that Halkett assumed the user would be carrying in any event. Boat-cloak Halkett designed a waterproof cloak made from an early form of Macintosh cloth, cotton impregnated with India rubber by using naphtha as a solvent. The lining of the cloak contained an airtight and watertight inflatable ovoid, split into four separate airtight compartments in case of puncture, and a pocket containing a paddle blade and a small bellows. The wearer of the cloak would carry a walking stick, which would double as the shaft of the paddle, and a large umbrella to serve as a sail. The cloak weighed around in total, and took three to four minutes to inflate; once inflated, it could support the weight of six to eight people. In early 1844, Halkett successfully tested a prototype boat-cloak on the River Thames, paddling it without taking on any water, despite, in his words, being "met by—passed by—and almost run down by—various Metropolitan Steamers plying to and fro in their several vocations, and causing no little commotion in the troubled waters of the River". Buoyed by this success, he took the prototype boat-cloak with him while on naval service, using it whenever the opportunity arose to test it under various sea conditions. In November 1844, Halkett hoped to test the boat-cloak in bad weather conditions, in the rough seas of the Bay of Biscay, but the weather was unusually calm. He was forced to take down his umbrella, and paddle, recalling later that "the winds that day were too civil by half, and the sleepless bay almost quite dormant". The boat-cloak was positively received by explorers; John Richardson (who had almost died during the 1819–1822 Coppermine expedition) wrote that "Had we been possessed of such a contrivance in our first expedition, I have little doubt of our having brought the whole party in safely". Halkett's boats in the Canadian Arctic Spurred on by the successful testing of the boat-cloak, Halkett designed a larger version that folded into a knapsack. When inflated, it could carry two men, operating a paddle on each side,